<template>
  <div class="helper">
    <!-- {{unFinishedTodoLength}}调用计算属性 -->
    <span class="left">剩余{{unFinishedTodoLength}}未完成</span>
    <!--<span class="tabs">-->
      <!--&lt;!&ndash; 唯一的key，如果下一次循环key相同会复用 &ndash;&gt;-->
      <!--<span-->
        <!--v-for="state in states"-->
        <!--:key="state"-->
        <!--:class="[state, filter === state ? 'actived' : '']"-->
        <!--@click="toggleFilter(state)">-->
          <!--{{state}}-->
      <!--</span>-->
    <!--</span>-->
    <span
      class="clear"
      @click="clearAllCompleted">
        清除已完成
    </span>
  </div>
</template>
<script>
  export default {
    props: {
      // 当前要选中的tab
      filter: {
        type: String,
        required: true
      },
      todos: {
        type: Array,
        required: true
      }
    },
    // data () {
    //  return {
    //    states: ['all', 'active', 'completed']
    //  }
    // },
    computed: {
      unFinishedTodoLength () {
        return this.todos.filter(todo => !todo.completed).length
      }
    },
    methods: {
      /**
       * 清除所有
       */
      clearAllCompleted () {
        this.$emit('clearAllCompleted')
      }
      /**
       * 修改状态
       */
      // toggleFilter (state) {
      // 把tab的状态传递给父主键
      //  this.$emit('toggle', state)
      // }
    }
  }
</script>
<style lang="stylus" scoped type="text/stylus">
  .helper {
    font-weight 100
    display flex
    justify-content space-between
    padding 5px 0
    line-height 30px
    background-color #ffffff
    font-size 14px
    font-smoothing: antialiased;
  }

  .left, .clear, .tabs {
    padding 0 10px
    box-sizing border-box
  }

  .left, .clear {
    width 150px
  }

  .left {
    text-align left
  }

  .clear {
    text-align: right
    cursor pointer
  }

  .tabs {
    width 200px
    display flex
    justify-content space-around
    * {
      display inline-block
      padding 0 10px
      cursor pointer
      border 1px solid rgba(175, 47, 47, 0)
      &.actived {
        border-color rgba(175, 47, 47, 0.4)
        border-radius 5px
      }
    }
  }
</style>
